Trying to realistically deform an inflated balloon so that it retains its volume
I found a solution that gave the more dramatic expansion that I was hoping for. First, as @Markus von Broady mentioned, lowering the cloth modifiers tension, but in addition I added pressure to the simulation when an object with collision put pressure on the system. So I added key-frames to the 'Pressure' setting that coincided with the system getting more pressure from an external force.